Reactive control in environments with hard and soft hazards

In this paper we present a generalization of reactive obstacle avoidance algorithms for mobile robots operating among soft hazards such as off-road slopes and deformable terrain. A new hazard avoidance scheme generalizes constraint based reactive algorithms [1], [2] from hard to soft hazards. Reactive controllers operate by directly parameterizing the closedloop dynamics of the system with respect to the environment the robot is operating in. Traditionally, reactive controllers are parameterized by weighting virtual attraction and repulsion forces from goals and obstacles [3], [4]. One pitfall of such parameterizations is sensitivity of the tuning parameters to the operating environment. A reactive controller tuned in one set of conditions is not applicable in another (e.g. a different density of obstacles). The algorithm presented in this paper has two key properties which are significant i) Parameterization is environment independent. ii) It can deal with non-binary environments that contain soft hazards.